When we refer you to some topic in the Emacs manual, you can read this manual node inside Emacs (assuming nothing is broken) by typing C-h i m emacs <RET> m topic <RET>.
This invokes Info, the GNU hypertext documentation browser. If you don't already know how to use Info, type <?> from within Info.
If we refer to topic:subtopic, type C-h i m emacs <RET> m topic <RET> m subtopic <RET>.
If these commands don't work as expected, your system administrator may not have installed the Info files, or may have installed them improperly. In this case you should complain.
If you are reading this FAQ in Info, you can simply press <RET> on a reference to follow it.
See Getting a printed manual, if you would like a paper copy of the Emacs manual.